Refining hydrocarbon fractions



United States Patent 3,152,069 PSEFlNTNG HYDRGCARBON FRACTTONS Raymond Wynl-zoop, Gladwyne, Shirley C. Bartlett, En,

liroornall, Albert T. Olenaalt, Swarthrnore, and lvor W.

Mills, Gienelden, Pa, assignors to Sun Oil Company,

Philadelphia, Pa, a corporation of New lersey No Drawing. Filed May 2, 1963, tier. No. 277,473

29 Claims. (Cl. 203-274) This invention relates to the treatment of mineral oils that boil generally in the lubricating oil range for the purpose of improving their qualities for various industrial uses. The invention is particularly useful for preparing various specialty oils which have superior resistance to oxidation in the presence of metals, for example, transformer oils, cable oils, refrigerator oils and the like.

The invention will be described more specifically with reference largely to the preparation of electrical oils, for example, transformer oils. In the use of such oils in transformer service it is important for the oil to have a high resistance to oxidation, especially in the presence of metals such as iron and copper; and it is often required that the oil should not contain any added oxidation inhibitor. Hence an effective method of treating a transformer oil stock that will produce an oil of high oxidation resistance is highly desirable.

Commercial transformer oils customarily are tested by the Doble Oxidation Test for electrical insulating oils developted by the Doble Engineering Company of Belmont, Mass. This procedure has been described in ASTM Standards on Electrical Insulating .eiquids and Gases, pages 3073l3, December 1959, under the title Suggested Method of Test for Oxidation Characteristics of Mineral Transformer Oil. It involves bubbling air through a known amount of the oil held at a temperature of 95 C. in the presence of copper and iron and making two types of tests daily on small samples of the oil. One type of test is an acidity measurement. The other is a precipitation test in which one volume of the oil is diluted with five volumes of pentane, the mixture is allowed to stand at least eight hours and the presence or absence of a sludge precipitate is noted. The endpoint of the Doble Test is taken as the number of days of oxidation either before the acidity of the oil reaches 0.25 mg. of KOl-l per gram or before a positive precipitation test for sludge is obtained. The best commercial transformer oils heretofore available generally have a life of only about three days under Doble Test conditions. Longer life values could be obtained by adding an oxidation inhibitor to the oil but the use of such additive traditionally has been considered unacceptable by transformer manufacturers and users.

An amplification of the Doble Test recommended by the Doble Engineering Company is the so-called Power Factor Valued Oxidation (PFVO). This involves operating in the manner described above but also determining the power factor of the oil at two hour intervals throughout the oxidation period. A curve is obtained by plotting the power factor against the oxidation time. Commercial transformer oils when tested by the PFVO Doble Test characteristically give a power factor curve that exhibits a sharp hump during the earlier stages of oxidation. The power factor rapidly increases to a value considerably in excess of two percent, following which it decreases to a relatively low value for a time and thereafter continuously rises indicating progressive oxidation. This behavior appears to be characteristic for all transformer oils produced by conventional refining procedures and seems to be related to the catalytic eifect of copper which becomes solubilized in some form in the oil as the oxidation test proceeds.

Another procedure for determining the oxidation stability of electrical oils in the presence of copper, commonly known as the Continental Oxidation Test, is described at pages 314-317 in ASTM Standards on Electrical Insulating Liquids and Gases, December 1959. Results of this test are expressed in terms of hours before a given amount of oxygen absorption has occurred under certain oxidation conditions. Results of this test and the above-mentioned Doble Test are given in the specific examples described hereinafter.

A conventional procedure for refining oils to make transformer or other electri al oils involves a preliminary solvent extraction such as extraction with furfural, treatment of the resulting raffinate with concentrated sulfuric acid typically in amount of 20 lbs./bbl. and then treatment with adsorptive clay typically in amount of 35 lbs./ bbl. For transformer oil stocks derived from paratllnic crudes, this type of treatment generally is capable of producing refined oils having a 3-day life in the Doble Oxidation Test although their power factor curves typically are as described above. With stocks derived from naphthenic crudes and having viscosity-gravity constants in the range of 0.34-0.92, this type of treatment generally is not successful in producing a 3-day Doble Test oil and the power factor curve usually is above acceptable levels. Hence a more effective type of treatment is needed with oils of this kind.

It has now been found that transformer oils having outstanding oxidation stability by the Doble Test can be prepared, and the oxidation resistance of mineral oils for use in contact with metals in general can be improved, by a refining procedure which includes the use of an alkali metal alkoxide as treating agent. The metal component of the alkoxide cm be sodium, potassium or alloys of sodium and potassium, and the alkoxide portion thereof must conform to certain structures as hereinafter fully described. The method is especially useful for making transformer oils of outstanding quality from naphthenic petroleum distillates having viscosities in the range of 50-65 S.U.S. at F.

According to the invention, mineral oils of improved oxidation stability are prepared by contacting a petroleum distillate oil stock boiling above 400 F. with an alkoxide formed from either sodium, potassium or sodium-potassium alloys and a non-primary alcohol having a 3-10 carbon atoms per molecule and thereafter separating metal-containing material from the treated oil. The alkoxide either can be formed in situ in the oil by adding the alkali metal and an appropriate alcohol separately or can be pre-formed before addition to the oil. When this type of treatment is used in combination with sulfuric acid and clay treatments, transformer oils having substantially fiat power factor curves by the Doble PFVO Test and exceedingly good oxidation resistance in the presence of copper can be obtained.

The alkoxide used in practicing the present invention must be derived from an alcohol which is either a secondary or tertiary alcohol, as primary alcohols are not operative for the present purpose. It is permissible for the alcohol to be a diol or triol provided that all hydroxyl groups are either secondary or tertiary. The alcohol can be either aliphatic or cycloaliphatic. In the latter case the alcohol preferably is tertiary. The preferred alcohols are isopropanol and tertiary butanol, but other alcohols of the C C range which are either secondary or tertiary are suitable. Examples are isopropanol, 2-butanol, tertiary butanol, 3-methyl-2-butanol, tertiary pentanol, 2- hexanol, 3-hexanol, 3-ethyl-3-pentanol, 2,2,3-trimethyl-4- pentanol, 2,4-dimethyl-3-ethyl-4-hexanol, cyclohexanol, 1-methylcyclopentanol, 1,3-dimethylcyclohexanol and the like.

In either embodiment of the invention, i.e., when the alkoxide is pre-formed or when it is formed in situ in the oil, the amount of alkali metal present in the alkoxide should be in the range of 0.15.0% by weight on the oil and more preferably 0.32.5%. When a pre-forrued alkoxide is employed, it can be used either with or without excess alcohol. In the embodiment where the alkoxide is formed in situ in the oil to be treated by adding the alkali metal and alcohol separately, the molar ratio of alcohol to alkali metal preferably should be at least 1:1 so that all of the alkali metal will be converted to the alkoxide. Free alkali metal is not itself an effective treating agent for improving oxidation stabilities as measured by the tests discussed above, and hence the use of an excess of the metal relative to the alcohol merely increases the costs of the treatment without providing any benefit. However the presence of excess alkali metal in the reaction mixture is not otherwise detrimental; hence molar ratios of alcohol to alkali metal below 1:1, e.g., 0.8:1 or even much lower, are permissible. Since the use of excess alkali metal would, in a commercial operation, necessitate providing means for recovering it for further use, it is distinctly advantageous to use a molar ratio of alcohol to alkali metal of at least 1:1 in preparing the alkoxide treating agent.

Practice of the process by separately adding the sodium and alcohol and forming the alkoxide in situ in the oil is the preferred embodiment of the invention, since this avoids a separate step of pre-forming the alkoxide. In this embodiment it is desirable to contact the oil, metal and alcohol utilizing vigorous agitation sufiicient to disperse the metal in finely divided form so that it can readily react with the alcohol to produce the alkali metal alkoxide. Temperatures from below room temperature (e.g. 50 F.) up to the cracking temperature of the oil can be used, but temperatures below 500 F. generally are employed and it is preferable to use a temperature considerably below 500 F., e.g. temperatures in the range of 175400 F. In practicing this embodiment of the process when the temperature is above the boiling point of the alcohol used, the reaction should be carried out either under pressure or with a reflux condenser attached to the reactor in order to prevent loss of alcohol from the system.

The reaction of the alkali metal, alcohol and the oil components is exothermic and an immediate rise in temperature will be noted when the alcohol, sodium and oil are intimately admixed. Contacting of the mixture is continued until the reaction is complete as indicated by no further release of heat. The time of contact will vary depending upon such factors as the nature of the charge oil, reaction temperature, degree of dispersion of the sodium and the like; but it generally will be in the range of minutes to 3 hours.

In the embodiment employing pre-formed alkoxide, the reagent conveniently can be prepared by finely dispersing sodium in a small amount of the oil to be treated preferably at a temperature above the melting point of the sodium, and reacting the dispersion with the alcohol. The so-prepared reagent generally is in the form of a slurry of the alkoxide in the oil. This can be added to the oil to be treated in amount such that the sodium content is 0.15.0% by weight based on the oil and more preferably 0.3-2.5 by weight. The mixture can be reacted at any desired temperature in the range of 50500 F. but preferably a temperature in the range of 175-400" F. is utilized. In this case a temperature rise during the reaction is not particularly evident as it is in the other embodiment of the invention. A reaction time of the order of 5 minutes to 3 hours should be allowed depending upon the temperature employed. In this embodiment of the invention, the reactor need not be maintained under pressure or be provided with a reflux condenser to prevent escape of alcohol.

Following the treatment of the oil with alkali metal alkoxide as described above, metal components are removed from the reaction mixture by settling, centrifugation or filtering. If desired the oil can be washed with water and treated with adsorptive clay to insure removal of all the metal components, although this is not generally essential for practicing the invention.

In the preparation of transformer or other electrical oils having outstandingly good oxidation resistance, it is desirable to combine the above-described alkali metal alkoxide treatment of the oil stock with additional steps of acid and clay treating. These steps can be employed beneficially either before or after the alkoxide treatment, or the acid treatment can be applied before and the clay treatment after the alkoxide treatment. Better results generally are obtained by carrying out the acid treatment of the oil before rather than after the treatment with alkali metal alkoxide. Typically this treatment may involve the use of relatively small acid and clay dosages, for example, 10 lbs./bbl. of concentrated sulfuric acid and l020 lbs./bbl. of adsorptive clay, as compared to the relatively larger amounts of these materials employed in the conventional treatment hereinbefore mentioned. Furthermore, the use of the alkoxide treatment in combination with acid and clay treating steps employing relatively small amounts of acid and clay produces oils which have much better oxidation stability as measured by the Doble Test than those obtained by conventional refining. By way of example, a naphthenic oil having a viscosity of about 55 S.U.S. F. and a viscosity-gravity constant of 0.85 3 was extracted with furrfural and the rafiinate was treated conventionally with 20 lbs./bbl. of 99% sulfuric acid followed by 35 lbs./-bbl. of clay. This gave an oil which had only a 2-day Doble life and hence was not considered particularly good for commercial transformer service. In comparison, when the same oil without any extraction is treated with only 10 lbs./bbl. of 99% sulfuric acid, then is treated according to the present invention with sodium isopropoxide in amount equivalent to 0.5% by weight of sodium based on the oil, and thereafter is contacted with as little as 2 lbs./bbl. of clay, oils having Doble life of up to 21 days, for example, are produced. An improvement is also obtained by employing the acid and clay after instead of before the alkoxide treatment. l '1 The following examples illustrate the invention more specifically:

EXAMPLE I The charge oil was a naphthenic distillate stock of boiling range suitable for electrical transformer use. The oil initially had the following properties: ARI. gravity =24.4; flash point=280 F.; fire point=3l0 F.; S.U.S. viscosity 100 F.=55.3; S.U.S. viscosity 210 F: 33.6; nitrogen content=50 p.p.m.; sulfur content=1.l8%; refractive iudex=l.5009; Doble life of a sample which was furfural extracted and then treated with 20 lbs./bbl. of 99% acid and 35 lbs./bbl. of clay=2 days. The foregoing Doble Test life indicates that conventional-treatment of this oil does not produce a high quality transformer oil.

The charge oil was first treated with 99% sulfuric acid in amount of 20 lbs./bbl. followed by 2 lbs./hbl. of coagulation clay to remove reaction products, and then was neutralized with caustic soda, water washed and air-dried. A 50 galebatch of the oil was charged to a pressure reactor provided with a high speed stirrer and 0.5% by weight of sodium was added and dispersed therein by vigorous agitation. Isopropanol was added in amount such that the molar ratio of the alcohol to sodium was 1.1 to- 1 and the mixture was stirred vigorously at a temperature of about F. for 35 minutes to effect complete reaction of the sodium and alcohol. The mixture was then heated to 280 F. and stirred for an additional 35 minutes to complete the reaction betweenthe sodium isopropoxide and the oil. Thereafter the reaction mixture was given two successive washes with 40% by volume of water a1 cacao in each wash to remove sodium compounds. After each wash the mixture was allowed to settle and the water layer was withdrawn from the reactor. The oil was dried by blowing it at 225 F. with nitrogen for 30 minutes and then contacted at the same temperature for 30 minutes with adsorptive clay in amount of 5 lbs./bbl. Finally the mixture was pumped from the reactor through a filter to remove the clay.

Table I shows a comparison of the properties of the oil refined as described above with the acid treated charge oil prior to treatment with the sodium isopropoxide.

Table 1 Acid Alkoxide Treated Treated Charge Oil A.P.I. Gravity 25. 3 25.3 Viscosity S.U.S./100 F 58.4 58.4 Aromatics, wt. percent-.. 34. 6 34. 5 Sulfur, wt. percent 0.11 0.11 1\itr0gen, p.p.m 4 1 Continental Om'dation, hrs. 34 78 Doble Oxidation Test:

Life, days 2 16 Acid No. at 72 hrs, mg. KOH/g 0. 11 None PFVO Curve:

Peak (hrs) Yes (20) None Percent Power Factor:

hrs 0.1 0. 1 1. 5 0. 2 8.9 0. 3 4.0 0. 3 1. 3 0. 3 1. 7 0. 3 4. 5 0.4 10. O. 24011IS 0.7

The data in Table I show that the oil prepared according to the present invention is markedly superior as a transformer oil to the acid treated charge which is representative of a transformer oil prepared according to conventional methods. In both the Continental and Doble Oxidation Tests the alkoxide treated oil is shown to have much better oxidation stability in the presence of copper. The data given for the PFVO curve shows that the conventional type oil exhibits a distinct hump in the power factor curve in the earlier stages of oxidation and that in later stages of oxidation the power factor rises sharply. On the other hand the PFVO curve for the alkoxide treated oil shows no hump whatever and rises only slight ly even during prolonged oxidation. Even after 240 hours (10 days) of oxidation the power factor for the latter oil was only 0.7%. The data also show that the alkoxide treatment has essentially no effect on sulfur content of the oil.

EXAMPLE 11 Another naphthenic distillate oil was used for making an insulating oil for electric cables. The charge oil had the following properties: A.P.l. gravity: 17.9; fiash point :495" R; fire point=570 F.; S.U.S. viscosity 210 F.:134.3; sulfur content=0.30%. This material was first extracted with furfural under conditions yielding 85% raffinate and one portion of the rafiinate was treated in conventional manner with 10 lbs./bbl. of 93% sulfuric acid followed by 30 lbs./bbl. of clay, the product being herein designated as Cable Oil A. Another portion of the raffinate was treated with 2.5% by weight of sodium with the addition of 1% by volume of isopropanol and thereafter carbon dioxide was bubbled through the mixture. The temperature level for these treatments was in the range of 330400 F. After separation of sodiumcontaining components from the oil, it was then treated with 10 lbs./bbl. of 93% sulfuric acid followed by 30 1bs./bbl. of clay, the product being herein designated as Cable Oil B. Samples of the two oil products thus obtained were held at 115 C. for 96 hours in contact with a copper strip in a test simulating conditions of cable 6 oil use. They were then tested for dissipation factor and resistivity with results as follows:

Dissipation Resistivity Factor a at C.

Cable Oil A 0. 0808 0. 24 Cable Oil B 0. 0193 1. 04

EXAMPLE 111 An oil which was the 500-1000 F. fraction resulting from catalytic cracking of gas oil in the presence of a silica-alumina catalyst was used as charge material in the present example. It had an A.P.I. gravity of 14.5 and a viscosity of about 100 S.U.S. 100 F. This material was treated at about 300 F. with 2.5% by weight of sodium with 1% isopropanol added and thereafter was blown with carbon dioxide at about the same temperature. The treated oil was tested as an electrical oil inhibitor by blending 1% by volume thereof into a commercial capacitor oil and subjecting the blend to an aging test. For comparison, the same test was made on the capacitor oil itself and on a blend of it with 1% of the catalytically cracked stock which had not been given any treatment. The aging test involved maintaining an open beaker of the oil in the presence of a copper strip and lead filings at a temperature of 100 C. and making certain tests on small samples of the oil after certain aging times. The following data were obtained:

Blendwith Blendwith No 1% Un- 1% Na-CO Additive treated Treated Additive Additive Before aging:

D.F. 0.0035 0 0059 0. 0030 2 22. 8 2. 28 6. 96 140 Hrs. aging:

0. 3902 0. 3012 0. 0110 14 1. 0. 5 0. 1 Pb content, p.p.m 5

1 D.F.=dissipation factor at 100 C. 2 R=resistivity at 100 C. in megmegohins. 3 Too small to measure.

A comparison of these data shows that the presence of the untreated catalytic material in the capacitor oil had little efiect in preventing the dissipation factor from increasing and the resistivity from decreasing. However, presence of the alkoxide treated material substantially inhibited these undesirable changes. Also it had a remarkably beneficial efiect in preventing copper and lead from being taken up in the oil.

EXAMPLE IV A sample of the acid-treated and neutralized charge oil similar to that used in Example I was treated batchwise with tertiary butoxide as the treating agent. The alkoxide was prepared by dispersing 0.5% by weight of sodium in the oil while hot, cooling to room temperature and slowly adding 1.1 moles of tertiary butanol per mole of sodium. The mixture was then heated to about 280 F. and agitated for 30 minutes, following which the mixture was blown with carbon dioxide at about 280 F. for 20 minutes. Sodium-containing material was removed from the mixture by settling. The treated oil had a Doble Test life of 5 days.

By way of comparison, when this run was repeated, except that n-propyl alcohol in one case and ethyl alcohol in another case were substituted for tertiary butyl alcohol, the Doble Test life was only 2 days which was the same value as obtained for the charge oil before treatment. This indicates that primary alcohols are not operative for the present purpose.

EXAMPLE V Untreated Treated Continental life, hrs 8 16 Slight Oxidation, percent sludge 12.3 7. 7

These results show that the alkoxide treatment substantially improved the oxidation stability of the oil.

EXAMPLE VI A gas oil boiling in the range of 415-680" F. and derived from a naphthenic crude having a V.G.C. of 0.892 was distilled into 20% fractions and portions of each fraction were treated in accordance with the invention using sodium isopropoxide as treating agent. All of the alkoxide treatments involved dispersing 0.5% by weight of sodium in the oil, adding isopropanol in amount equivalent to a 10% stoichiometric excess relative to the sodium, agitating for 10 minutes at room temperature to form the alkoxide and then agitating for 30 minutes at 280 F. Metal-containing components in the product were removed by water washing and clay contacting. Continental oxidation values from check tests for the fractions before and after these treatments are shown in Table II.

These results indicate that the degree of improvement etfected in the oxidation stability of oils by treatment in accordance With the invention can vary depending upon the boiling range of the oil even though the oils are derived from the same crude stock. However a distinct improvement in resistance to oxidation in the presence of copper is obtained by alkoxide treatment of any fraction throughout the gas oil boiling range.

The foregoing examples specifically illustrated ways of practicing the present invention. Substantially equivalent results are obtained by substituting potassium or potassium-sodium alloys for the sodium. Likewise substantially equivalent results are obtained by substituting other secondary and tertiary alcohols for isopropanol or tertiary butanol. While in some of the foregoing examples the reaction mixtures after the treatment with alkoxide were blown with carbon dioxide, substantially the same results are obtained when the carbon dioxide is omitted. The

i5 invention can be used to advantage in treating numerous types of petroleum oil fractions boiling above 400 F. other than those shown in the specific examples.

This application is a continuation-in-part of applicatial Serial No. 94,433, filed March 9, 1961, which in turn is a continuation-in-part of application Serial No. 15,810, filed March 18, 1960, both of which are now abandoned.

We claim:

1. Method of treating a petroleum distillate oil boiling above 400 F. to improve oxidation stability in the presence of copper which comprises contacting such oil with an alkoxide formed from a metal selected from the group consisting of sodium, potassium and sodium-potassium alloys and an alcohol having 3-10 carbon atoms and selected from the group consisting of aliphatic and cycloaliphatic secondary and tertiary alcohols, and separating metal-containing material from the treated oil.

2. Method according to claim 1 wherein said alkoxide is formed in situ in the oil by separately adding thereto the metal and the alcohol.

3. Method according to claim 2 wherein the metal is sodium in amount of 0.1-5 0% by Weight on the oil.

4. Method according to claim 3 wherein contacting of the oil is eiiected at a temperature in the range of 400 F.

5. Method according to claim 3 wherein the alcohol is isopropanol.

6. Method according to claim 3 wherein the alcohol is tertiary butanol.

7. Method according to claim 2 wherein the amount of alcohol used is at least the stoichiometric amount required to form the alkoxide with the metal.

8. Method according to claim 1 wherein said alkoxide is pre-formed prior to addition to the oil.

9. Method according to claim 8 wherein the alkoxidc is a sodium alkoxide having a sodium content equivalent to 0.1-5.0% by weight on the oil.

10. Method according to claim 9 wherein the alkoxide is sodium isopropoxide.

11. Method according to claim 9 wherein the alkoxide is sodium tertiary butoxide.

12. Method according to claim 1 wherein the mineral oil also is treated with concentrated sulfuric acid and thereafter is contacted with adsorptive clay.

13. Method of preparing an oil of superior oxidation resistance particularly useful for electrical applications from a hydrocarbon distillate oil having a viscosity-gravity constant in the range of 0.84-0.92 which comprises adding to said oil a metal selected from the group consisting of sodium, potassium and sodium-potassium alloys in amount of 0.15.0% by weight of metal based on the oil and an alcohol having 3-10 carbon atoms and selected from the group consisting of aliphatic and cycloaliphatic secondary and tertiary alcohols, the molar ratio of said alcohol to the metal being at least 0.8:1, intimately contacting the mixture at a temperature in the range of 175400 F., and separating metal-containing material from the treated oil.

14. Method according to claim 13 wherein the metal is sodium.

15. Method according to claim 14 wherein the alcohol is isopropanol.

16. Method according to claim 14 wherein the alcohol is tertiary butanol.

17. Method according to claim 13 in which the oil is also contacted with concentrated sulfuric acid and thereafter with adsorptive clay.

18. Method of preparing a hydrocarbon oil of superior oxidation resistance which comprises treating a petroleum distillate oil boiling in the lubricating oil range with concentrated sulfuric acid, removing reaction products and excess acid from the oil, adding to the oil sodium in amount of 0.15.0% by weight on the oil and a nonprimary alcohol having 3-4 carbon atoms, the molar ratio 0f a d a c hol '[0 the sodium being at least 0.8:1, agitating 0 the mixture at a temperature in the range of 50500 E, and separating sodium-containing material from the treated oil.

19. Method according to claim 18 wherein the amount of sodium is 0.32.5% by Weight on the oil.

20. Method of preparing transformer oil of superior oxidation resistance from a naphthenic distillate oil having a viscosity in the range of 5065 S.U.S. at 100 F.. and a viscosity-gravity constant in the range of 0.84-0.92 which comprises treating the oil with sulfuric acid and thereafter with adsorptive ciay, then contacting the oil at a temperature in the range of 175400 F. With sodium iso- 10 propoxicle in amount equivalent to 03-25% by Weight of sodium based on the oil, and separating metal-containing material from the treated oil.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,503 Milmore July 18, 1939 2,614,966 Vanderbilt Oct. 21, 1952 2,773,805 Vanderbilt et a1 Dec. 11, 1956 FOREIGN PATENTS 526,863 Great Britain Sept. 26, 1940 

1. METHOD OF TREATING A PETROLEUM DISTILLATE OIL BOILING ABOVE 400*F. TO IMPROVE OXIDATION STABILITY IN THE PRESENCE OF COPPER WHICH COMPRISES CONTACTING SUCH OIL WITH AN ALKOXIDE FORMED FROM A METAL SELECTED FROM THE GROUP CONSISTING OF SODIUM, POTASSIUM AND SODIUM-POTASSIUM ALLOYS AND AN ALCOHOL HAVING 3-10CARBON ATOMS AND SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC AND CYCLOALIPHATIC SECONDARY AND TERTIARY ALCOHOLS, AND SEPARATING METAL-CONTAINING MATERIAL FROM THE TREATED OIL. 